Method of attaching copper fins to cast-iron cylinders



Feb. 9 1926.

C. P. GRIMES METHOD OF ATTACHING COPPER FINS T0 CAST IRON CYLINDERS Filed April 4. 1.924

IN VEN TOR. 9%

A TTORNEYS to the intake and exhaust manifolds of the 1 engine and also the bosses 7 in which the valve stems are guided. The mold is alsoformed with an annular cavity 8 in which the heat radiating fins Q'preferably having angular, c'ircumferentially extending flanges '9 at their outer margins are arranged with Y cool gradually and at substantially the same the margins 10 extending into the cavity 2,

i the fins being surrounded by sand or other material to hold them in place. Usually, so-v called green sand is packed between the fins.

The mold is further formed with an annuv lar cavity 11 around the annular fin cavity 8 and spaced therefrom by a wall or core 11 of sand or other suitable material, The

mold or the core 12 thereof is also formed with inlet pass'ages 13-, for the molten metal,

' time-the lower portion of the mold cavity,

that is, that portion forming pipe connections 5, 6 and the head 4 of the cylinder, is filled up, the passages'13 are also filled and also the entrancelti for such passages, so that the molten metal will also flow through laterally extending passages 17 from the passages 13-into the cylindrical mold cavity 2 and, as these lateral passages 17 are located near the upper ends of the fins 9, the molten metal starts to flow-downwardly along the marginsof the fins :from'- their upper ends toward; their lower-ends at about the same time that the metalstarts to flow from the lower ends of the fins toward their upper; ends. Such pouring of the metal, so that it flows along the margins of the fins from the lower ends toward the upper end and from the upper end toward the lower prevents the burning ofit or weakening of the fins and causes themxtobe united equally throughout their length to the casting. Also the fact that the fins are cold prevents undue burning, fusion, weakening or destruction of the margins 10.

The mold is also provided with vent passages or gas outlets 18 and 19, the-passage 18 extending to the lower end of the cylindrical cavity 2, so as to permit the immediate escape of the gases formed from the casting Thus all thegases formed duringthe cast- 7 ing operation are free to escape immediately and not remain in the mold cavities.

of the casting. The casting and the heating metal 'inthe cavity 11 are then allowed to rate. I

Owing to the fact that the gases'have been allowed to escape, as soon as formed, explosion ofisuch gases, which would otherwise occur if the metal werepoured into the cavity 11 before such gases had escaped or before or during the casting of the metal into the mold cavity 2, is avoided, and further owing to the fact that the heating metal is poured into the cavity 11 after the metal is poured into the cavity 2 against the mar gins of the cool fins 8, firm, integral, homogeneous joints are formed between the fins and the cast iron and the cast iron is substantially homogeneous throughout. 7

As here shown,'the mold casing consists of a lower or base section22 in which the cavities 14 are formed for forming the pipe connections5, 6 and associated parts, an intermediate section 23 in which is located the portion (if the mold cavity 2 forming that part of the cylinder to which the fins are attached and also in which the annular chamber 11 for the heating medium is located, and an upper section 24 mounted on ortion of the cylinder not provided with eat radiating The annular wall orcore 11 is placed within the section 23 around the outer ends of the fins. A cylindrical'core 26 is placed within the-sections 23, 24 to form the cylindrical mold cavity 2 and this core is formed with the pouring passages 13 and with the gas outlets 18, 19. The cylindrical core has a head 27 at its upper end within the entrance cavity 16.

Many methods have been tried and at ented for attaching copper fins to cast iron cylinders but such methods have proven failures or at the most partial successes, due to the fact that the joint between the fins and the cylinder is not firm or to the fact that the fins chill and harden the metal of the casting and the resulting joints are not good heat conductors and such hardened joints change the texture of the metal to such extent that the cylinders cannot be satisfactorily machined.

By my process, owing to the fact that the cast iron is first brought around the comparatively cold' fins, undue fusing or burning of the margins of the fins with which the metalcomes in contact is avoided and, owing to the after heating of the fins, undue chilling of the metal of the cylinder the section 23 and shaped toreceive the sand or core 25 which forms the ieo is avoided and equal cooling of the metal of the cylinder and of the fins is brought about, so that firm, secure joints are formed which are rapid conductors of heatand the texture of the cast iron is homogeneous.

' Furthermore, owing to the fact that the gases formed in the cores and in the mold mold cavity to form the cylinder. The

pouring of this heating metal, after the cylinder has been cast but wh'ilethe metal.

of the cylinder is in molten condition, effects three main results:

A. It permits the metal of thecyhnder to be first cast around comparatively cool fins. B. lit avoids explosion of-the gases l b- 'erated during the casting of the cylinder.

C. It contributes to forming of firm, heat conducting joints between the cylinder and the fins.

What I claim is 1. The method of attaching toa metal part, fins of a metal having a' greater. coelficient .ofexpansion than said metal part,- comprising supporting the fins with mar-t gins thereof projecting into a mold cavity which forms the metal part to which the fins are to be attached, pouring the metal into such mold cavity, whereby it flows around the margins of the fins, while the fins are comparatively cool, and then after the pouring of said metal, heating the fins to a temperature approximating that of the molten metal of said part, and permitting the molten metal and the heating means to cool gradually.

2. The process of attaching to a metal part, fins ofa metal having a difi'erentcoefiicient of expansion than said metal part, consisting in pouring molten metal to form said part around and in contact margins of the fins, heating thei'fins after the pouring of the metal to a temperature approximately that of the molten metal andpermitting the molten metal and the heating means to 'cool gradually at. substantially the same rate.

3. The method of attaching to a metal part, fins of a metal having a greater coeificient of expansion, than the metal of said part consisting in supporting the fins with margins thereof projecting into a mold cavity, pouring the molten metal which is to form the part to which the fins are to be attached, into the mold cavity to flow from the bottom of the mold cavity upwardly along the margins of the fins, and also to fiow downwardly in the mold cavity along the margins of the fins from the upper ends thereof toward the lower.

4. The method of attaching to a metal part, fins of a metal having a greater coefficient of expansion, consisting in supporting the fins with margins thereof project-'- ing into a mold cavity, pouring the molten metal which is to form the part to which the fins are to be attached into the mold cavity to flow from'the bottom of the mold cavity 1 upwardly along the margins of the fins, and

also'to flowdownwardly in the mold cavity along the margins of the fins from the upper ends 'there'ofitoward the lower, there after heating the fins to a temperature approximating the temperature of the molten metal and allowing the molten metal and the heating means to cool gradually at substantiallythesame rate. e I

5.v The process of attaching cast iron'cylin'ders, heat radiating fins, of a metal hav ing greater co-efiicient of expansion than cast iron, comprising pouring cast iron into amold cavity into which the margins of the fins project,,while the fins are comparatively cool, and thereafter heating the fins by a heating medium to'a temperature approximating that of the molten metal in the mold cavity, and permitting the metal of the a casting and the heating means to cool gradually at substantially the same rate.

6. The method of attaching to cast iron cylinders, fins of a metal having a greater co-efiicient of expansion than cast iron, comprising pouring the iron into a mold cavity in which the margins of the'fins are exposed, and causing the metalto flow from along the margins of the fins from the lower ends of the fins toward the upper ends thereof, and from the upper ends of the fins toward the lower ends thereof.

7. The method of attaching to cast iron cylinders, fins of ametal having" a greater co-efficient ofeXpa-nsion than cast iron, comprising pouring the iron into a mold cavity in which the margins of the fins-are exposed while such fins are comparatively cool, causing the metal to flow along the margins of the fins from the lower ends of thefins toward the upper ends thereof, and from the ends thereof, heating the fins to approxh mately the temperature of the molten metalv by a heating medium, and allowing the casting andthe heating medium to cool gradually at substantially the same rate.

8. The method of attaching to cast'iron cylinders, heat radiating fins of a metal having greater co-efiicient of expansion than iron consisting in supporting the fins'with margins thereof projecting into the mold cavity for forming the cylinder, pouring the molten iron into the cavity to flow from the bottom of the cavity tip-permitting the escape of gases formed in the mold during the casting operation and heating the fins after the escape of the greater portion of said gases, and permitting the casting and the heating means to lcool at substantially the same rate.

9. The method of attaching to cast iron cylindersyfins of a metal havingagreatery eo-efiicient of expansion than cast iron, comprising pouring the iron into .a 'mold cavity in which the margins of the fins are exposed, and causing the metal to flow from along the margins of the fins from the lower ends of the fins toward the upper ends thereof; and from thel'lpper ends of the fins toward the lower ends thereof, permitting the gases formed during the casting operation toeseape, heating the-fins after the gases or greater, portions thereof have escaped, to a temperature approximating or greater than that of the casting, after the escape of such gases, and allowing the casting and the heating means for the fins to 0001'.

In testimony whereof, I have hereunto signed my name, at Syracuse, in the. county of Onondaga, and in the State of New York, this 24th day of March,'1924.

I CHARLES P. GRIMES. 

